(Vancouver, WA)  --  Authorities say a body found in the Columbia River near Beacon Rock is believed to be that of a Vancouver woman who was reported missing.  Forty-four-year-old Daphne Alexander-Christ was last seen March 7th.  Her station wagon was found later that week on the Washington side of the Gorge.  Police say the body was found by hikers yesterday and was tentatively identified as that of Alexander-Christ.